<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        var score = prompt("请输入分数")
        // 80 优秀 60 良  60 不及格
        // if(score >= 80){
        //     console.log('优秀')
        // }else{
        //     if(score>60){
        //         console.log('良')
        //     }else{
        //         console.log('不及格')
        //     }
        // }
        if(score < 80){
            if(score>60){
                console.log('良')
            }else{
                console.log('不及格')
            }
           
        }else{
            console.log('优秀')
        }
    </script>
</body>
</html>